File indexing completed on 2024-05-12 05:43:30

 /*
     Copyright (C) 2015 Volker Krause <vkrause@kde.org>
 
     This program is free software; you can redistribute it and/or modify it
     under the terms of the GNU Library General Public License as published by
     the Free Software Foundation; either version 2 of the License, or (at your
     option) any later version.
 
     This program is distributed in the hope that it will be useful, but WITHOUT
     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
     License for more details.
 
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
 #include "dependencysorter.h"
 #include <checks/dependenciescheck.h>
 #include <elf/elffileset.h>
 
 #include <QDebug>
 #include <QHash>
 
 #include <cassert>
 #include <elf.h>
 
 void DependencySorter::sortDtNeeded(ElfFileSet* fileSet)
 {
     assert(fileSet->size() > 0);
 
     auto file = fileSet->file(0);
     if (!file->dynamicSection())
         return;
 
     // TODO index SO_NAME, this probably should be moved to ElfFileSet, we have that in a bunch of places now
     QHash<QByteArray, int> nameIndex;
     for (int i = 0; i < fileSet->size(); ++i) {
         const auto f = fileSet->file(i);
         if (!f->dynamicSection())
             continue;
         const auto soName = f->dynamicSection()->soName();
         if (nameIndex.contains(soName)) {
             qWarning() << "Suspicious DT_NEEDED entry '" << soName << "' in " << f->fileName() << ", aborting.";
             return;
         }
 
         if (!soName.isEmpty())
             nameIndex.insert(soName, i);
     }
 
     // count usages
     QVector<int> usageCounts;
     const auto needed = file->dynamicSection()->neededLibraries();
     usageCounts.resize(needed.size());
     for (int i = 0; i < needed.size(); ++i) {
         auto depFile = fileSet->file(nameIndex.value(needed.at(i)));
         assert(depFile);
         assert(file != depFile);
 
         usageCounts[i] = DependenciesCheck::usedSymbolCount(file, depFile);
     }
     qDebug() << usageCounts;
 
     // sort, check if change is needed
     QVector<int> sortedNeededIndex;
     sortedNeededIndex.resize(needed.size());
     std::iota(sortedNeededIndex.begin(), sortedNeededIndex.end(), 0);
     assert(sortedNeededIndex.size() == usageCounts.size());
     qDebug() << sortedNeededIndex;
 
     std::sort(sortedNeededIndex.begin(), sortedNeededIndex.end(), [usageCounts](int lhs, int rhs) {
         return usageCounts.at(lhs) > usageCounts.at(rhs);
     });
 
     qDebug() << sortedNeededIndex;
 
     // since we modify the file in-place, get the necessary string table values before we do that
     QVector<uint64_t> neededValues;
     neededValues.resize(needed.size());
     int neededIndex = 0;
     for (uint i = 0; i < file->dynamicSection()->header()->entryCount(); ++i) {
         auto dynEntry = file->dynamicSection()->entry(i);
         if (dynEntry->tag() != DT_NEEDED)
             continue;
         neededValues[neededIndex++] = dynEntry->value();
     }
 
     // open target file
     ElfFile newFile(file->fileName());
     if (!newFile.open(QFile::ReadWrite) || !newFile.isValid()) {
         qWarning() << "Can't open" << file->fileName() << "for writing.";
         return;
     }
 
     // write change
     neededIndex = 0;
     auto newDynSection = newFile.dynamicSection();
     for (uint i = 0; i < newDynSection->header()->entryCount(); ++i) {
         auto dynEntry = newDynSection->entry(i);
         if (dynEntry->tag() != DT_NEEDED)
             continue;
 
         dynEntry->setValue(neededValues.at(sortedNeededIndex.at(neededIndex)));
 
         qDebug() << needed.at(sortedNeededIndex.at(neededIndex));
         ++neededIndex;
     }
 
 }